WASHINGTON (Reuters) - President Donald Trump said on Friday that U.S. military personnel had deployed to Gabon in response to possible violent demonstrations in the Democratic Republic of Congo after a presidential election there.

In a letter to congressional leaders, Trump said the first of about 80 military personnel arrived in Gabon on Wednesday in case they are needed to protect U.S. citizens and diplomatic facilities in Congo’s capital Kinshasa.

He said they “will remain in the region until the security situation in the Democratic Republic of the Congo becomes such that their presence is no longer needed.”

Trump said additional forces may deploy to Gabon “if necessary.”

Congo’s electoral commission is scheduled to release provisional results of the presidential election on Sunday, but it has said there could be delays because of the slow arrival of tally sheets.

Observers and the opposition say the election was marred by serious irregularities. Congo’s government says the election was fair and went smoothly.

The international community has raised concerns that a disputed result could cause unrest, as was the case after the 2006 and 2011 elections.

On Thursday, the U.S. State Department called on the electoral commission to ensure votes were accurately counted and threatened to impose sanctions against those who undermined the process or threatened peace and stability in the country.